Sequential microwave-ultrasound-assisted silver nanoparticles synthesis: A swift approach, their antioxidant, antimicrobial, and in-silico studies

The present research work unravels the novel optimization of microwave-ultrasound-assisted rapid synthesis of Olea europaea capped silver nanoparticles (O-AgNps) as a capping and stabilizing agent that is not previously studied. The synthesized O-AgNps were characterized using UV-Visible spectroscopy, Fourier transform infrared spectroscopy (ATR-FTIR), proton nuclear magnetic resonance (1H NMR), dynamic light scattering-zeta potential (DLS-Zeta potential), high-resolution transmission electron microscopy-energy dispersive X-ray spectroscopy (HR-TEM-EDAX), and atomic force microscopy (AFM) techniques. The HR-TEM-EDAX revealed that O-AgNps were ti 10 nm in diameter with a polydispersity index of 0.191 and were spherical to elliptical. The nanoparticles were analysed for the in-vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant, agar-well diffusion antibacterial assay, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) assays. The results were promising with a half-maximal inhibitory concentration (IC50) of 155.08 1./g/mL for the antioxidant assay. The antimicrobial agar-well diffusion assay showed maximum zones of 24.9 +/- 0.14 mm diameters at 8 mg/ mL for Staphylococcus aureus (S. aureus) and 24.5 +/- 0.7 mm at 8 mg/mL for Escherichia coli (E. coli). The MICs and MBCs were 156.25 1./g/mL and 625 1./g/mL for the antimicrobial assays against S. aureus and E. coli. Additionally, the research throws limelight on the in-silico molecular docking analysis using AutoDock Vina software and arrives at a possible elucidation to support the experimental work. (c) 2021 Elsevier B.V. All rights reserved.